393 motorola sensor device data www.motorola.com/semiconductors $"$ "##%" # " ! $ !"$%" ! #$ "$ the MPX4250D series piezoresistive transducer is a stateoftheart monolithic silicon pressure sensor designed for a wide range of applications, particularly those employing a microcontroller or microprocessor with a/d inputs. this transducer combines advanced micromachining techniques, thinfilm metallization, and bipolar processing to provide an accurate, highlevel analog output signal that is proportional to the applied pressure. the small form factor and high reliability of onchip integration make the motorola sensor a logical and economical choice for the automotive system engineer. features ? differential and gauge applications available ? 1.4% maximum error over 0 to 85 c ? patented silicon shear stress strain gauge ? temperature compensated over 40 to +125 c ? offers reduction in weight and volume compared to existing hybrid modules ? durable epoxy unibody element applications ? ideally suited for microprocessor or microcontrollerbased systems pins 4, 5 and 6 are no connects for unibody device figure 1. fully integrated pressure sensor schematic v s sensing element v out gnd thin film temperature compensation and gain stage #1 gain stage #2 and ground reference shift circuitry
semiconductor technical data
integrated pressure sensor 0 to 250 kpa (0 to 36.3 psi) 0.2 to 4.9 volts output pin number note: pins 4, 5, and 6 are internal device connections. do not connect to external circuitry or ground. pin 1 is noted by the notch in the lead. basic chip carrier element case 867, style 1 gauge port option case 867b, style 1 1 2 3 v out gnd v s 4 5 6 n/c n/c n/c unibody package dual port option case 867c, style 1 rev 3
394 motorola sensor device data www.motorola.com/semiconductors maximum ratings (1) parametrics symbol value unit maximum pressure (2) (p1 > p2) p max 1000 kpa storage temperature t stg 40 to +125 c operating temperature t a 40 to +125 c notes: 1. t c = 25 c unless otherwise noted. 2. exposure beyond the specified limits may cause permanent damage or degradation to the device. operating characteristics (v s = 5.1 vdc, t a = 25 c unless otherwise noted, p1 > p2, decoupling circuit shown in figure 3 required to meet electrical specifications.) characteristic symbol min typ max unit pressure range (1) p op 0 e 250 kpa supply voltage (2) v s 4.85 5.1 5.35 vdc supply current i o e 7.0 10 madc minimum pressure offset (3) (0 to 85 c) @ v s = 5.1 volts v off 0.139 0.204 0.269 vdc full scale output (4) (0 to 85 c) @ v s = 5.1 volts v fso 4.844 4.909 4.974 vdc full scale span (5) (0 to 85 c) @ v s = 5.1 volts v fss e 4.705 e vdc accuracy (6) (0 to 85 c) e e e 1.4 %v fss sensitivity d v/ d p e 18.8 e mv/kpa response time (7) t r e 1.0 e msec output source current at full scale output l o + e 0.1 e madc warmup time (8) e e 20 e msec offset stability (9) e e 0.5 e %v fss notes: 1. 1.0 kpa (kilopascal) equals 0.145 psi. 2. device is ratiometric within this specified excitation range. 3. offset (v off ) is defined as the output voltage at the minimum rated pressure. 4. full scale output (v fso ) is defined as the output voltage at the maximum or full rated pressure. 5. full scale span (v fss ) is defined as the algebraic difference between the output voltage at full rated pressure and the output voltage at the minimum rated pressure. 6. accuracy (error budget) consists of the following: ? linearity: output deviation from a straight line relationship with pressure over the specified pressure range. ? temperature hysteresis: output deviation at any temperature within the operating temperature range, after the temperature is cycled to and from the minimum or maximum operating temperature points, with zero differential pressure applied. ? pressure hysteresis: output deviation at any pressure within the specified range, when this pressure is cycled to and from the minimum or maximum rated pressure, at 25 c. ? tcspan: output deviation over the temperature range of 0 to 85 c, relative to 25 c. ? tcoffset: output deviation with minimum rated pressure applied, over the temperature range of 0 to 85 c, relative to 25 c. ? variation from nominal: the variation from nominal values, for offset or full scale span, as a percent of v fss , at 25 c. 7. response time is defined as the time for the incremental change in the output to go from 10% to 90% of its final value when s ubjected to a specified step change in pressure. 8. warmup is defined as the time required for the product to meet the specified output voltage after the pressure has been stab ilized. 9. offset stability is the product's output deviation when subjected to 1000 hours of pulsed pressure, temperature cycling with bias test. mechanical characteristics characteristics typ unit weight, basic element (case 867) 4.0 grams
395 motorola sensor device data www.motorola.com/semiconductors figure 2. crosssectional diagram (not to scale) fluorosilicone die coat wire bond lead frame die stainless steel metal cover rtv die bond p1 p2 epoxy case 1.0 f ips 470 pf output vs 5 v 0.01 f gnd vout figure 3. recommended power supply decoupling and output filtering. for additional output filtering, please refer to application note an1646. figure 2 illustrates the differential/gauge pressure sensing chip in the basic chip carrier (case 867). a fluorosilicone gel isolates the die surface and wire bonds from the environ- ment, while allowing the pressure signal to be transmitted to the sensor diaphragm. the MPX4250D series pressure sensor operating charac- teristics and internal reliability and qualification tests are based on use of dry air as the pressure media. media, other than dry air, may have adverse effects on sensor performance and longterm reliability. contact the factory for information regarding media compatibility in your application. figure 3 shows the recommended decoupling circuit for in- terfacing the output of the integrated sensor to the a/d input of a microprocessor or microcontroller. figure 4 shows the sensor output signal relative to pres- sure input. typical, minimum, and maximum output curves are shown for operation over a temperature range of 0 to 85 c using the decoupling circuit shown in figure 3. the output will saturate outside of the specified pressure range. 0 output (volts) 5.0 4.5 4.0 3.5 3.0 pressure in kpa max min 0 10 20 30 40 50 60 70 80 100 110 120 130 140 150 160 170 180 190 200 210 2.5 2.0 1.5 1.0 0.5 figure 4. output versus differential pressure 250 260 90 typ transfer function: v out = v s * (0.00369*p + 0.04) error v s = 5.1 vdc temp = 0 to 85 c
396 motorola sensor device data www.motorola.com/semiconductors ordering information the MPX4250D series silicon pressure sensors are available in the basic element package or with pressure port fittings that provide mounting ease and barbed hose connections. device type/order no. options case no. marking MPX4250D basic element 867 MPX4250D mpx4250gp gauge ported element 867b mpx4250gp MPX4250Dp dual ported element 867c MPX4250Dp transfer function (MPX4250D) nominal transfer value: v out = v s x (0.00369 x p + 0.04) nominal transfer value: (pressure error x temp. factor x 0.00369 x v s ) nominal transfer value: v s = 5.1 0.25 vdc temperature error band temp multiplier 40 3 0 to 85 1 +125 3 temperature in c 4.0 3.0 2.0 0.0 1.0 40 20 0 20 40 60 140 120 100 80 temperature error factor pressure error band pressure (kpa) pressure error (max) 0 to 250 kpa 3.45 kpa 75 100 125 150 175 200 225 25 50 250 note: the temperature multiplier is a linear response from 0 to 40 c and from 85 to 125 c. 4.0 3.0 2.0 1.0 0 1.0 2.0 3.0 4.0 5.0 5.0 0 pressure error (kpa)
|
